畜禽养殖废弃物资源化利用技术发展分析

近年我国畜禽养殖业发展迅速,而养殖废弃物资源化利用技术显得相对滞后,未经处理的畜禽粪便随意堆放,造成空气、水体以及土壤的污染,危害身体健康.养殖废弃物污染防治迫在眉睫,其资源化利用是从源头上防治污染的有效手段.为此,本文对养殖业废弃物的污染状况、资源性质、技术状况等进行总结,对各种养殖废弃物资源化技术,如能源化、肥料化、饲料化等技术进行分析,从而明确我国养殖废弃物资源化利用技术的发展方向.     

Analysis of sedimentation and resuspension processes of aquaculture biosolids using an oscillating grid

Sedimentation and resuspension processes of aquaculture biosolids (non-ingested feed and faeces) are analysed using vertically oscillating grids as a source of turbulence in fluid tanks. An oscillating grid system consists of a container in which a grid is stirred vertically generating a well-known turbulent field that is function of amplitude and frequency of oscillation, distance between grid and measurement point, and mesh spacing of the grid. The grid used in this study had a mesh spacing of 1.2 cm, and was calibrated using different amplitudes (1, 1.5 and 2 cm), frequencies (from 1 to 6 Hz) and distances (2.4, 2.7 and 3 cm). After calibration, the turbulence needed to resuspend biosolids and to maintain them in the water column following different times of consolidation, and with biosolids of different origin, was analysed. It was observed that the turbulence needed to resuspend aquaculture biosolids increased with the time of consolidation. When the turbulence was decreased after a resuspension process, the next sedimentation of biosolids showed a hysteretic behaviour: turbulence needed to resuspend a fixed percent of biosolids from the tank bottom is substantially higher than that needed to maintain the same percentage suspended in the water column. Differences in resuspension behaviour of biosolids originated in different tanks were also observed.

The method provides useful information that can be compared with turbulence generated by fish swimming activity, in order to determine the culture conditions, which can promote self-cleaning conditions in a particular tank.     

氨基酸平衡的低蛋白和杂粕日粮对蛋鸡粪中臭味物质含量的影响

研究了以可消化氨基酸为基础配制的5种日粮对蛋鸡粪中吲哚、粪臭素和挥发氨等臭气化合物含量的影响。结果表明:应用氨基酸平衡的低蛋白日粮饲喂蛋鸡,鸡粪中吲哚、粪臭素和粪氨含量比对照组分别降低了37.98%、42.61%和53.95%,比玉米-棉粕-菜籽粕组分别降低了64.38%、76.84%和69.91%,差异显著(P<0.05)或极显著(P<0.01);用菜籽粕和棉菜籽粕日粮饲喂的蛋鸡,粪中有机酸含量高于大豆粕日粮(P<0.05),说明杂粕日粮虽然对蛋鸡生产性能影响不大,也降低了饲料成本,但同大豆粕日粮相比,粪中臭味物质的排放量大大增加。     

The levels of zearalenone and its metabolites in plasma,urine and faeces of horses fed with naturally,Fusarium toxin–contaminated oats

Concentration profile of zearalenone (ZON) and its metabolites in plasma, urine and faeces samples of horses fed with Fusarium toxin–contaminated oats is described. In plasma, β‐zearalenol (β‐ZOL) was detected at high levels on day 10 of the study (3.21–6.24 μg/l). β‐Zearalenol and α‐zearalenol were the major metabolites in urine. Zearalenone, α‐ZOL and β‐ZOL were predominantly found in faeces. Zearalanone could also be detected in urine (1.34–5.79 μg/l) and faeces (1 μg/kg). The degree of glucuronidation was established in all sample types, approximately 100% in urine and plasma. Low per cent of glucuronidation (4–15%) was found in faeces samples. The results indicate the main conversion of ZON into β‐ZOL in horse. This finding could explain why horse is not susceptible to ZON in comparison with swine which produce α‐ZOL as a predominant metabolite.     

微生物除臭剂在畜禽粪处理中的作用

通过微生物除臭剂在畜禽粪便处理中的应用研究,结果反映,菌剂中丰富的快生型细菌在物料发酵前期迅速增殖,使发酵料迅速升温,比不加除臭剂处理提前2~3d进入高温期,碱性挥发物减少,臭味减轻2~3个级别。     

山羊粪便总DNA提取方法的比较

本试验比较了从山羊粪便中提取总DNA的四种方法的优缺点,旨在为后续实验提供合适的提取方法。笔者首先采用PBS缓冲液过夜处理粪便标本,继而通过酚-氯仿抽提法、CTAB抽提法、天根试剂盒法和OMEGA试剂盒法提取样品总DNA。结果显示：酚-氯仿抽提法提取的DNA完整性不好,且纯度低;CTAB法提取的DNA浓度和纯度都较高,但完整性不好;试剂盒法提取方便,操作简单,时间短,但提取的浓度较低,其中天根试剂盒法提取的DNA纯度高,完整性好。综合考虑,天根试剂盒法是提取山羊粪便总DNA的最佳方法。     

Determination of total potassium in vegetation and sheep faeces contaminated with soil

Abstract

Samples of vegetation and faeces from heavily grazed pastures are likely to be contaminated with soil to some extent. The determination of total potassium on these samples will result in low recoveries if a wet oxidation procedure normally used for vegetation analysis is employed. However, data are presented which show that for the sites studied satisfactory recoveries of total potassium are obtained following a sulphuric acid‐hydrogen peroxide digestion, providing the ash content of the sample does not exceed 25%. For ash contents greater than 25%, alkaline fusion or hydrofluoric/perchloric acid decomposition procedures are required to obtain full recovery.     

An investigation of obligate and facultative anaerobes in bovine mastitis

Abstract

AIMS: To investigate the prevalence of Campylobacter spp. and C. jejuni in dog faecal material collected from dog walkways in the city of Palmerston North, New Zealand, and to characterise the C. jejuni isolates by multilocus sequence typing (MLST) and porA and flaA antigen gene typing.

METHODS: A total of 355 fresh samples of dogs faeces were collected from bins provided for the disposal of dog faeces in 10 walkways in Palmerston North, New Zealand, between August 2008–July 2009. Presumptive Campylobacter colonies, cultured on modified charcoal cefoperazone deoxycholate plates, were screened for genus Campylobacter and C. jejuni by PCR. The C. jejuni isolates were subsequently characterised by MLST and porA and flaA typing, and C. jejuni sequence types (ST) were assigned.

RESULTS: Of the 355 samples collected, 72 (20 (95% CI=16–25)%) were positive for Campylobacter spp. and 22 (6 (95% CI=4–9)%) were positive for C. jejuni. Of the 22 C. jejuni isolates, 19 were fully typed by MLST. Ten isolates were assigned to the clonal complex ST-45 and three to ST-52. The allelic combinations of ST-45/flaA 21/porA 44 (n=3), ST-45/flaA 22/porA 53 (n=3) and ST-52/ flaA 57/porA 905 (n=3) were most frequent.

CONCLUSIONS: The successful isolation of C. jejuni from canine faecal samples collected from faecal bins provides evidence that Campylobacter spp. may survive outside the host for at least several hours despite requiring fastidious growth conditions in culture. The results show that dogs carry C. jejuni genotypes (ST-45, ST-50, ST-52 and ST-696) that have been reported in human clinical cases.

CLINICAL RELEVANCE: Although these results do not provide any evidence either for the direction of infection or for dogs being a potential risk factor for human campylobacteriosis, dog owners are advised to practice good hygiene with respect to their pets to reduce potential exposure to infection.     

饲粮中添加发酵豆粕对断奶仔猪粪便菌群多样性的影响

本试验采用高通量测序技术,研究饲粮中添加发酵豆粕对断奶仔猪粪便菌群多样性的影响。选取36日龄“杜×长×大”仔猪80头,随机分为A、B、C、D组,D组为对照组,饲喂基础饲粮;A、B、C组为试验组,分别在基础饲粮中添加5%、10%、15%的发酵豆粕。试验结束采集4组仔猪的粪便,采用Illumina MiSeq高通量测序技术对其中细菌的16SrRNA基因的V3~V4区序列进行测序。结果表明:1)菌群的平均有效序列数为47218条;在97%的相似水平下共产生了3581个操作分类单元(OTUs);共检测到12个门、21个纲、33个目、64个科、111个属和137个种。2)α多样性指数在各组间均无显著性差异(P>0.05),但B组的Shannon指数最高,菌群最丰富。β多样性分析表明,4组菌群在统计学上存在显著差异(P<0.05),分组效果较好。3)门水平的优势菌为厚壁菌门,科与属水平的优势菌分别为乳酸菌科和乳酸菌属。B组的厚壁菌门相对丰度显著高于D组(P<0.05),乳酸菌属相对丰度显著高于A、D组(P<0.05),但与C组间差异不显著(P>0.05)。4)菌群主要参与的代谢通路为糖类代谢、氨基酸代谢、能量代谢、核酸代谢、辅酶和维生素代谢。除核酸代谢外,其余4种代谢通路中,B组菌群的相对丰度最高并依次为C、A、D组。综上所述,在仔猪饲粮中添加10%的发酵豆粕,能增加肠道菌群的多样性,显著增加肠道中厚壁菌门、乳酸菌科和乳酸菌属等有益菌的相对丰度,维持肠道的健康,促进营养物质的代谢。